1. Technical Field
The present invention relates to a snack piece turnover device and method of using the same. More particularly, the invention relates to a snack piece turnover device employing a curved conveyor, which uses centrifugal force to turn snack pieces over, and the method of using the same.
2. Description of Related Art
Snack pieces are known to be prepared with the use of flyers. Generally, snack pieces such as potato and corn crisps are formed from dough and are sheeted and cut into discrete pieces (preforms) for treatment. Treatment involves cooking the preforms in a fryer to produce cooked snack pieces. Particularly with potato and corn crisps, a form fryer is beneficial because performs, which are sheeted and cut pieces of uncooked dough, can be molded and cooked into a desired product shape.
The dough comprises a substantially dry mixture of potato flakes and sugar. Other substances that may be utilized include starches for their ability to improve the texture, consistency, and durability of food products and to improve the processing of dough into food products. One or more emulsifiers may also be used for their ability to improve the processing of dough. After forming uncooked snack pieces, they can be processed into finished molded snack pieces.
A desirable feature of molded snack pieces is that they can be made uniform in size and shape. With uniformity, the snack pieces can be packaged in a seated alignment. This allows snack product to be packed in a canister rather than in a loose bag. Canister packaging provides a degree of protection against breakage of the snack pieces while providing improved transportability of the snack pieces both in bulk and in individual canisters. Also, canisters can be sealed with a lid after opening to deter product degradation.
For packaging of uniformly shaped product such as curved ellipses, (for example, an ellipse having its longer sides curved upward in the same direction) snack pieces are stacked first before filling in a canister. Snack pieces can be stacked one directly over another, or they can be partially overlapped in a similar manner as rooftop shingles are overlapped. After such overlapping, the product pieces are then pushed together so that each piece is directly over the other. While it is possible to stack curved product pieces either with concave sides up or concave sides down, the product pieces may be more amenable to stacking in one particular orientation, depending on the product shape.
For example, thin, elliptical product pieces having upwardly-curved sides are more easily stacked with their concave sides down rather than up. In the event that two adjacent product pieces fail to overlap, those pieces can only be forced to stack one over the other if their adjacent edges are at different heights. With their concave sides up, two adjacent elliptical product pieces cannot be stacked because their adjacent product edges would lie flat against the conveyor, and those edges would confront each other upon pushing the pieces together. With their concave sides down, however, the product pieces are able to rock back and forth on their downwardly curving edges in the direction of travel. This ability to rock makes it highly unlikely that the adjacent edges of two pieces would confront each other at the same vertical level. One product piece will thus be able to overlap and eventually stack over the other.
Because many form fryers produce concave-side-up snack pieces, such concave-side-up pieces must be flipped prior to packaging. FIG. 1 shows an example of a prior art snack piece-flipping device. The prior art flipping system 10 flips curved, elliptical snack pieces 12 from concave-side up to concave-side down using a vacuum suction roller 22. As shown, the snack pieces 12 have their longitudinal sides bent in the same direction, approximating a U-shape. The concave-side-up snack pieces 12 are conveyed on a wire-mesh type or other gas-permeable type of upper belt 20 towards the packaging stages. As the snack pieces 12 reach a vacuum suction roller 22 at the end of the upper belt 20, the snack pieces 12 are retained by vacuum to the surface of the upper belt 20 and moved around the end roller 22 until each snack piece 12 is inverted and above a lower belt 30, either right above or slightly downstream from the first roller 32 of the lower belt 30. Once inverted, the concave-side-down snack pieces 12 are released from the upper belt 20 and dropped onto the lower belt 30. The snack pieces 12 can then be stacked for packaging.
As is apparent, snack piece flipping technology allows snack pieces to be reoriented into positions more suitable for stacking. However, with prior art devices such as the vacuum roller 22 shown in FIG. 1, snack piece retention to the roller is critical to the flipping process. Vacuum rolls are problematic as snack piece retention is not particularly consistent or reliable. For instance, the vacuum roller 22 and the upper belt 20 shown in FIG. 1 are prone to clogging from debris. Clogging prevents the vacuum roller 22 from properly retaining control over the snack pieces 12, which may then drop prematurely from the vacuum roller 22. Another problem is that the snack pieces 12 can stick to the upper belt 20 for too long or too short a period of time. If the snack pieces are not released precisely at the same point over the lower belt 30, misalignment and/or breakage of snack pieces can occur. Furthermore, vacuum rolls require a significant amount of energy to create the necessary suction force. Therefore an improved, more efficient and reliable flipping device and method are desired to avoid these problems.